feed: open files using blocking io by default, allow optional flags parameter in open_file()

Signed-off-by: Michael Ira Krufky <mkrufky@linuxtv.org>
linuxtv_tuner: open dvr device using nonblocking io

Signed-off-by: Michael Ira Krufky <mkrufky@linuxtv.org>
dvbtee v0.3.4

Signed-off-by: Michael Ira Krufky <mkrufky@linuxtv.org>
Merge branch 'master' into teev-qt